Trammel-head.



P. c. & H. s. JEWBLL.

TRAMMEL HEAD.

, APILIOATION FILED SEPT. 30, 1910.

998,616. Patented July 25,1911.

COLUMBIA PLANMRAPH 00., WASHINGTON, D. c.

AES PATEN '1 FREDERICK G. JEWELL AND HENRY S. JEWELL, OF CHICAGO, ILLINOIS.

TRAMMEL-I-IEAD.

Specification of Letters Patent.

Patented July 25, 1911.

Application filed September 30, 1910. Serial No. 584,606.

To (LZZ whom it may concern:

Be it known that we,-FREDnRIoK G. JEW- ELL and HENRY S. JnwnLL, citizens of the United States, residing at Chicago, in the county of Cook and State of Illinois, have invented certain new and useful Improvements in Trammel-Heads, of which the following is a specification.

This invention relates to trammel heads, and has for its primary object to provlde an improved construction for devices of this nature according to which a trammel head may be constructed cheaply and durably, -and adapted to be positioned on a beam at any desired point without the necessity of threading it on the end of the beam and sliding it lengthwise thereon into the desired position.

Another object is to provide an improved construction for trammel heads according to which a trammel head shall be adapted for use with any width of beam.

Other and further objects will appear in the specification and be specifically pointed out in the appended claims, reference being had to the accompanying sheet of drawings exemplifying the invention, and in which Figure 1 is a perspective view of a trammel or beam-compass. Fig. 2 is a side elevation of a portion of the beam with a pencil-holding trammel head mounted thereon. Fig. 3 is a transverse section of one form of beam showing the application thereto of ourimproved trammel head. Fig. 4 is a similar transverse view of a beam of different form showing our improved trammel head in end elevation. Fig. 5 is a section on the line V-V, Fig. 2.

Referring more specifically to the drawings, and to the embodiment shown therein, the trammel shown in Fig. 1 comprises a beam 1 which is preferably rectangular in cross section, having on one end a pencil supporting trammel head 2, and on the other end a spur holding trammel head 8. As shown in Fig. 2, the pencil holding trammel head 2 comprises in the embodiment shown, a sheet metal strip bent in the form shown in Fig. 2 to provide a pair of divergent resilient wings 4:, 5, projecting from the horizontal portion 6. Rigidly secured to the portion 6 in any suitable manner, preferably by being riveted thereto, is a spur socket 7 adapted to receive the pencil holding spur 8, which in the usual manner is slotted below and provided with a tubular hole for the reception of a piece of lead 9. An adjusting screw 10 enables this lead to be secured within the spur 8. As shown in Fig. 5, the spur 8 is provided with a pentagonal end 11 adapting it to fit a socket of the same shape in the end of the spur socket 7. As indicated by dotted lines in Fig. 2, when it is desired to move the trammel head along the beam 1, or to remove said trammel head from the beam, the wings 4- and 5 are pressed toward each other to unclamp said wings from the beam 1, said wings for this purpose being provided with recesses opening through the lateral edges thereof, which in the embodiment shown in Figs. 1, 2 and 3, correspond in depth with the width of the beam 1. In the embodiment shown in Fig. 4, however, the trammel beam 12 is made of greater thickness, so that the trammel head overreaches but a portion of the width of said trammel beam. As shown in Figs. 3 and 4, the steel pointed spurs 13 may be mounted upon the trammel head in a manner similar to that of the pencil holding head 8.

It is thought that the operation of this improved device will be clearly understood but briefly stated it is as follows. When it is desired to place one of the trammel heads upon the beam, the wings 4L and 5 are pressed toward each other into position perpendicularly with respect to the horizontal portion 6, at which time the said wings will be substantially parallel to each other. The head may then be placed upon the beam by inserting the beam into the slots laterally, and the slots therein will extend beyond the lateral edges of the beam 1. Then the trammel head is in the position desired with respect to the beam, the wings 4 and 5 may then be released and when thus released they will grip the beam resiliently. It will thus be seen that the head may be removed from the beam, adjusted with respect thereto, and replaced upon the beam without the necessity of sliding the head along the beam into the desired position.-

What we claim is:

1. In a beamcompass, a head having resilient portions for engaging the beam, said portions being provided with slots opening through the edges thereof to adapt the head to be moved transversely of the beam into clamping engagement therewith.

2. A trammel head for beam compasses provided with resilient wings having slots therein to slidably niount the head upon the of two subscribing Witnesses on this 26th beam, said slots being open through the latday of September A. D. 1910'.

eral edges of said Wings to adapt the head FREDERICK C. JEWELL. to be positioned along one edge of said HENRY S J EWELL. beam. Vitnesses:

In testimony whereof We have signed our J. H. JOGHUM, J 1:, names to this specification, in the presence C. H. SEEM.

Copies of this patent may be obtained for five cents each, by addressing the Commissioner of Patents.

Washington, D. C. 

